The Iris flowers.

Most of irises in this page are bearded irises. The other irises are Siberian (Iris sibirica) and yellow flag water iris (Iris pseudacorus). Bearded irises offer carefree blooms in nearly every color of the rainbow. Their ruffled flowers, set off by attractive, sword-like leaves, cover the spectrum from blues, yellows and soft pinks to lustrous whites and almost blacks. They are easy to establish and require a minimum of maintenance. Unlike most spring bulbs, bearded iris don't require a period of cold to produce blossoms, making them perfect for areas with mild winters.

Bearded irises are very cold hardy, USDA zones 3-9, the rhizomes need plenty of sun to bloom well and regularly. All pictures were taken from the Iris garden at the Missouri Botanical Garden in St. Louis, Missouri, USA.